Why is Dual Channel important? - TUXEDO Computers

What is dual channel?

According to the definition at Wikipedia, Dual Channel is an architecture that has been used for around 20 years, in which two or more main memory modules can be operated in parallel on a processor via separate data buses. The advantage is that more data can be transferred simultaneously via several buses between memory and CPU or between memory controller and CPU.

 Modern notebooks usually have two memory channels, each of which is equipped with one or more memory banks for plugging in memory modules. If there are several memory channels, it makes a difference whether the same amount of RAM is distributed over one or both channels. Thus, if 16 GBytes of RAM are to be installed, it makes sense to use 2 bars with 8 GBytes each instead of one bar with 16 GBytes. 

The testers at Holarse, a German platform for Linux gamers, also had to experience this when they wanted to compare two generations of the TUXEDO Polaris 15 and didn't pay attention to the memory allocation when putting together the components. Bernd Ritter, the operator of the platform, describes the experiences he had during the test due to the allocation error in a detailed article, which is certainly not only interesting for gamers. 

Test Environment

The test was about a comparison of generations 1 and 3 of the lightweight gamer notebook TUXEDO Polaris 15, which reached the market between September 2020 and August 2021. The two notebooks were each equipped with 32 GBytes of RAM, with the Polaris Gen 1 having 2 bars of 16 GBytes each, while the Gen 3 had only one bar of 32 GBytes. 

After the error was noticed through unexpected performance values, the testers at Holarse saw the chance to examine performance differences between single and dual channels more closely. TUXEDO Computers additionally provided two bars with the same clock rate, the same type designation and 16 GBytes each. This was important for the test because of the comparability, but in everyday use, the bars do not have to be identical and can come from different manufacturers as long as the capacity is identical in both channels.

Benchmarks

The measurements taken by the testers with different benchmark tools impressively prove the effects of using Dual Channel. In the single-core measurement with Geekbench, Gen 3 with single channel (1 × 32 GBytes) is superior to Gen 1 (2 × 16 GBytes) due to the stronger CPU (AMD Ryzen 7 4800H vs. AMD Ryzen 7 5800H), but as expected, shows a further increase when Gen 3 was tested with 2 bars.

It becomes even clearer in the multi-core CPU test: Here, Gen 1 with 2 CPUs is even clearly superior to Gen 3 with only 1 CPU, despite the better CPU. As expected, the Gen 3 with 2 CPUs outperforms the Gen 1.

Many more tests with and without a dedicated graphics card and various benchmarks like Unigine Superposition as well as with various games follow in the article, where the interaction of performance factors like CPU, RAM, GPU and hard drive is more important than in the benchmarks.

Conclusion

The article makes one thing clear: When putting together a new notebook in the configurator, you should go for dual channel for the sake of performance and order 2 bars of RAM. Bernd Ritter sums it up in conclusion:

"However, it provides quite a bit of performance in onboard GPU mode as well as in dedicated mode with an NVIDIA graphics card for most purposes. In summary, we can say that none of the scenarios are actually profitable or so important that you should rely on just one RAM bar. It saves insignificant money and you are then annoyed afterwards or grudgingly upgrade."